Field of the Invention
The present invention relates to a particle detector apparatus for optically ascertaining a number of particles arranged on a surface, in particular of a particle filter. The invention furthermore relates to a particle detection method for optically ascertaining a number of particles arranged on a surface, in particular of a particle filter.
Background Information
The particle detector apparatus is intended to be used to quantify the loading of fluids with certain particles, in particular microbiological particles, for example with bacteria. In particular, to this end the fluid to be analyzed is intended to be pressed through a particle filter in which the particles become mechanically fixed. Depending on the type of particles to be detected, marking substances are intended to be used, the effect of which is that the particles to be analyzed can be distinguished optically from the particle filter and from other particles.
In the prior art, it is known for example to treat bacteria with fluorescent substances, which emit light in certain colors according to the incident light and can therefore easily be distinguished from the surroundings. In the known particle detection methods, the total intensity of the emitted light is generally measured in order to determine the particle density. Other particle detection methods use complicated and expensive electron microscopes for determining the particle number.
Such detection methods require a large number of user operations for positioning the detectors and the particle filters. Furthermore, calibration of the measurement results is virtually impossible. There are no automated instruments which can carry out such a particle detection method. If a photomultiplier is used, then a cumulative signal is measured by which the number of particles present can only conditionally be deduced.